Allergy season: Nothing to sneeze at

(CNN) -- Feel like you can't breathe? Do you have the uncontrollable urge to rub your eyes every 10 seconds?

The trees are blossoming and shedding pollen early this year, and that's bad news for millions of Americans who are suffering from allergies.

You probably think your area has it the worst, but the true champion of allergies in America is Knoxville, Tennessee, according to the Asthma and Allergy Foundation of America.

The nonprofit organization, which is releasing its list of 100 allergy capitals next week at allergycapitals.com, bases its rankings on pollen score, how much allergy medicine is used per patient, and the number of board-certified allergists per patient -- in other words, how difficult it would be to get an appointment.

"There's a really obvious concentration of these capitals" in the mid-Atlantic regions and the South Atlantic regions, said Michael Tringale of AAFA. Knoxville is consistently in the top 10, and has been No. 1 several times, he said.

Allergy causes are everywhere

Knoxville has already had pollen counts above 6,000 particles per cubic meter, said allergist Dr. Robert Overholt, who works in the city. With the abundance of vegetation and lots of moisture, an early warm spell in Tennessee sets the area up for a high concentration of allergens such as oak, maple and pine pollen.

Tree pollen is usually worst in March, April and early May, while grass pollen is highest in April, May and June, Overholt said.

The "allergy capital" idea came about because the AAFA was flooded with phone calls from allergy patients asking, "Where should I move?" Tringale said.

Here's the harsh reality: There are few places in the country to hide if you have allergies, so you can't really move to avoid them. Some people actually develop allergies after they move, Overholt said. For reasons unknown, people who relocate commonly develop allergies to local pollens in their second year of residence, he said. People even have allergies in Arizona, a state that's relatively dry, but has growing vegetation, he said.

To determine America's "allergy capitals," AAFA takes into account the particles per cubic meter of common allergens such as tree, grass and weed pollen, as well as mold spores, and how many people are allergic to each of those. A high pollen score, a high allergy-medicine use score and a low number of certified allergists per patient move a city higher on the list.

Why allergies are on the rise

One theory behind worsening allergies is that global warming seems to be exacerbating the problem, Tringale said. Many of the warming seasons are starting earlier, and the cooling seasons don't last as long. More plants that never used to thrive in the South are thriving there because the climate may be warmer, he said.

"These plants are producing more pollen, not just because their seasons are longer, but each day because of the increase in carbon dioxide pollution, they produce more pollen per plant."

Another factor is pollution, which may be driving the immune system to develop allergies, Overholt said. There is also the hygiene hypothesis -- that the children in the United States grow up in too-clean households, so their immune systems go haywire.

What to do

There are several remedies available over the counter and by prescription to help treat the unpleasant symptoms of allergies.

People don't sleep well when their noses are stuffed, Overholt said. To help clear the nasal pathways, your doctor may prescribe a topical antihistamine spray such as Astepro or Patanase or a steroidal spray such as Flonase to relieve congestion.

As far as daily living, keep the windows of your car and house closed, and turn air conditioning on, he said. Still, you will get exposed to pollen as soon as you leave your car or house.

"Basically you're trapped, so you've got to use medications, you've got to use a desensitizing program," he said.

Desensitization therapy, otherwise known as allergy shots, is the only mostly sure-fire way to relieve allergies. This requires a three-year commitment, which is inconvenient, but provides substantial benefits, Overholt said. Patients typically see 50 percent reduction of symptoms by the end of one year and 90 to 100 percent after three years, Overholt said.

Web sites such as pollen.com have daily maps of pollen scores so you can see how bad the sniffles might be on that day.